Pad cure process for the preparation of deae cotton

ABSTRACT

THIS IS AN IMPROVED PROCESS FOR PREPARING DIETHYLAMINOETHYL COTTON. 2-CHLOROETHYLDIETHYLAMINE (DEAE) HYDROCHLORIDE IS FIRST REACTED WITH ALKALINE HYDROXIDE TO PRODUCE A WATER-INSOLUBLE LIQUID WHICH IS THEN THOROUGHLY MXED WITH A QUANTITY OF WATER AND IN A MATTER OF MINUTES IS CONVERTED TO A WATER-SOLUBLE DIETHYLAZIRIDINIUM CHLORIDE (DAC). THE PREPARATION OF DIETHYLAMINOETHYL COTTON CAN BE CARRIED OUT IN A ONE-STEP OPERATION WITH REAGENT CONCENTRATION OF UP TO A SATURATED SOLUTION, ABOUT 2 MOLAR, AND CAN BE ACCELERATED WITH BASE IN THE PAD BATH. THE PROCESS IS AMENDABLE TO CONTINUOUS OPERATION.

United States Patent 3,756,777 PAD-CURE PROCESS FOR THE PREPARATION OFDEAR-COTTON Earl J. Roberts, Clinton P. Wade, and Stanley P. Rowland,New Orleans, La., assignors to the United States of America asrepresented by the Secretary of Agriculture No Drawing. Filed July 30,1971, Ser. No. 167,814

Int. Cl. D06m 13/38, 13/34 US. Cl. 8-188 6 Claims mxed with a quantityof water and in a matter of minutes is converted to a water-solublediethylaziridinium chloride (DAC). The preparation of diethylaminoethylcotton can be carried out in a one-step operation with reagentconcentration of up to a saturated solution, about 2 molar, and can beaccelerated with base in the pad bath.

The process is amendable to continuous operation.

A non-exclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purposes of the UnitedStates Government, with the power to grant sublicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This invention relates to an improved process for the preparation ofdiethylaminoethyl cotton. More specifically, this invention relates tothe preparation of waterinsoluble 2-chloroethyldiethylamine by reactingan alkali hydroxide with 2-chloroethyldiethylamine hydrochloride toproduce a water-insoluble liquid. This liquid is converted to awater-soluble diethylaziridinium chloride upon 7 mixing thoroughly withwater. Any concentration of the diethylaziridinium chloride, up to asaturated solution, about 2 M (about 27%), can be employed to react withcotton, and the reaction can be accelerated by adding a quantity of baseup to or greater than the concentration of the diethylaziridiniumchloride (DAC).

Hartman, Guthrie, Bullock, and many others have reported the formationof diethylaminoethyl cellulose mainly in wet-process reactions ofcellulose with 2-chloroethyldiethylamine. It has also been reported that2-chloroethyldiethylamine dissolves in water to form thediethylaziridinium chloride. The present invention does not purportthese ideas as new. With respect to cotton fabrics, what this inventiondiscloses is a method of preparing the diethylaminoethyl cotton in a newone-step, dry-cure process, among other things.

PRIOR ART Roberts and Rowland report in the,Canadian J. of Chem. 45,page 261 (1967) this related work. Cotton fabric was padded to a 100%wet pickup in a 20% aqueous solution of 2-chloroethyldiethylaminehydrochloride.

The wet impregnated fabric was placed on a pin frame and immersed for 3minutes in an excess of 20% sodium hydroxde solution which was saturatedwith sodium sulfate. This impregnated fabric was placed inside apolyethylene bag and left there for 19 hours. It was then 3,756,777Patented Sept. 4, 1973 rinsed with 1 N acetic solution and water. Thenitrogen content of this cotton fabric after treatment was 0.39%.

Soignet et al. report in Textile Research J. 39, page 780 (1969) thisrelated work. Cotton fabric was padded to a 100% wet-pickup n a 20%aqueous solution of 2- chloroethyldiethylamine hydrochloride and reactedwith 8% sodium hydroxide at C. for about 10 minutes. The excess sodiumhydroxide was removed by washing the fabric in dilute acetic acid, thenwith water. A single treatment by this process yelded a finished fabricwith a nitrogen content of 0.4%. A higher nitrogen content was obtainedby repeated treatments.

Berni et al. report in Textile Res. J. 40, page 99 (1970), thepreparation of sodacellulose fabrics which are then inserted intocylinders which contain various concentrations of2-chloroethyldiethylamne in tertiary butanol, at room temperature. Forthis series reaction times were also varied. The reacted fabrics werethen removed, rinsed, and neutralized in dilute acetic acid and rinsedin water.

The main object of this inventon is to provide a drycure process for thepreparation of diethylaminoethyl derivatives of cotton, generallyreferred to as DEAE- cotton.

A second object of this invention is to provide a drycure method ofpreparing diethylaminoethyl derivatives of otherpolysaccharide-containing materials.

A third object of this invention is to provide a drycure method ofpreparing variations of the objects, such as the preparation of DEAEderivatives of starch, wood pulp, and regenerated cellulose.

Diethylaminoethyl (DEAE) cellulose has found considerable utility as anion-exchange material, especially in chromatographic separation of aminoacids, polypeptides, and proteins. DEAE-cotton has been prepared by avariety of procedures but we find these disadvantageous in that theyhave all been wet processes requiring multistep bath operations.

We further find disadvantageous the processes of the prior art in that asequence of steps is required in the preparation of the DEAE-cotton. Oneroute of preparation generally known is that of. dissolving the2-chloroethyldiethylamine hydrochloride in water, padding the cottonfabric, immersing the wet-impregnated cotton in sodium hydroxide, andkeeping the cotton immersed until it reacts. This we find inefficient,mainly because it is a wet cure, multiple step process. Another processinvolves elevating the temperature ofthe sodium hydroxide. The Berni etal. process (see above) presents the idea of preparing soda-cellulose,and while Wet with a nonaqueous solvent, solvent exchanging in order toemploy the solvent that the 2-chloroethyldiethylamine is compatible withand again submer-ging the soda-cellulose impregnated (still wet) in the2-chloroethyldiethylamine solution in a nonaqueous solvent and retain itimmersed until reaction occurs.

Now we have found the manipulations of the prior art to be unnecessary,and We have produced the DEAE derivatives of cotton and other cellulosicmaterial and starch in amore efficient manner. Firstly,2-chloroethyldiethylamine hydrochloride is mixed with aqueous sodiumhydroxide, or potassium hydroxide in a molar ratio of about from 1021 to1:1, thereby producing the insoluble 2-chloroethyldiethylamine which isa liquid at room temperature. Once this product is prepared it isseparated from the aqueous layer and mixed with water, shaken vigorouslyfor about from 5 to 20 minutes at room temperature and 3 the entirequantity is converted to the water-soluble diethylaziridinium chloride.Alternately, the DEAE hydrochloride may be mixed with base solution ofthe desired concentration and the mixture sha'ken until solution ishomogeneous.

APPLICABLE EQUATIONS a Et H01 NaOH N-CHgCHzCl Et (insoluble) Shake inwater to produce Cell-OH+ DAC Cell-O-CHzCHz-N NaOH Et cen-o-ornom-N(DEAE-Cellulose) Et The water-soluble DAC is most useful in padding ontopolysaccharide materials at concentrations up to a saturated solution(about 2 M, or approx. 27%). This reaction can be further accelerated byadding base to the padding solution. Once the polysaccharide isimpregnated, reaction can be carried out at the preferred 80 to 140 C.range. The time required is usually about 5 minutes. The reaction canalso be carried out at room temperature; 16 hours is a convenient timeto achieve the same reaction. The impregnating and reacting steps can berepeated as required to obtain the desired degree of substitution. Thereacted polysaccharide can be water-washed to remove unreactedmaterials.

Diethylaminoethyl cellulose prepared by this process retains 75 to 100%of the original breaking strength. The wrinkle recovery properties ofcellulosic fabric treated according to the process of this inventionwere essentially the same as those of the untreated fabric.

The following examples are provided to illustrate what can be done withthe process of the invention, and they should not be construed aslimiting the invention in any manner whatever.

EXAMPLE 1 A sample of cotton printcloth weighing 7.7 grams was utilized.It was thoroughly impregnaed with an aqueous solution containing 1 moleof diethylaziridinium chloride, and one equivalent of sodium carbonatein 1000 ml. of solution. The wet-impregnated fabric was passed throughsqueeze rolls to obtain a wet-pickup of 120%. The wet sample was placedin an oven and heated for 5 minutes at 140. The fabric was then removedfrom the oven and washed with flowing tap water for 30 minutes, anddried in air at room temperature. The nitrogen content of this samplewas 0.2%. Similar results are obtained with raw stock or yarn.

EXAMPLE 2 Using the solution of Example 1 the once-treated, washed anddried fabric of Example 1 was processed a second time exactly as before.Analysis of the twicetreated sample indicated a nitrogen content of0.36%.

EXAMPLE 3 Using the solution of Example 1 the twice-treated washed anddried fabric of Example 2 was processed a third time exactly as before.Analysis of the thrice-treated sample indicated a nitrogen content of0.48%.

EXAMPLE 4 Using the technique of Example 1 but varying the reagentsolution so that it would contain 1 mole of DAC and 1 mole of NaOH in1000 ml. of solution, a cotton printcloth sample was processed asbefore. Analysis of this sample indicated a nitrogen content of 0.48%.

EXAMPLE 5 Using the solution of Example 4 the once-treated, washed anddried fabric of Example 4 was processed a second time exactly as before.Analysis of the twicetreated sample indicated a nitrogen content of0.65%.

EXAMPLE 6 Using the technique of Example 1 but varying the reagentsolution so that it would contain 1 mole of DAC in 1000 ml. of solutionand no base, three samples of cotton printcloth were processed asbefore. One sample was washed and analysis indicated a nitrogen contentof 0.2%.

EXAMPLE 7 Using the solution of Example 6 the two remaining samples ofprintcloth from Example 6 were given a second treatment without beingwashed between treatments. One piece was washed and was found to contain0.38% nitrogen.

EXAMPLE 8 Using the solution of Example 6 the remaining sample ofprintcloth from Example 7 was given a third treatment without beingwashed between treatments. It was washed and was found to contaon 0.57%nitrogen.

EXAMPLE 9 The solution and technique of Example 5 were applied to acotton printcloth; however, the fabric was dried in air for 16 hours andthen heated for 5 minutes at 140 C. Analysis of this sample indicated anitrogen content of 0.15%.

EXAMPLE 10 The solutions and technique of Example 5 were applied tocotton printcloth; however, the fabric was dried in an oven for 5minutes at C. Analysis of this sample indicated a nitrogen content of0.15%. There was no significant difference between the finished sampleof Example 10 and the sample of Example 11.

EXAMPLE 11 A solution containing 2 M diethylaziridinium chloride wasprepared as previously described and cooled to 10 C. or lower but not tothe freezing point. To this solution was added an equal volume of 2 Nsodium hydroxide solution cooled to the same temperature. The lowtemperature slows the rate of hydrolysis of diethylaziridinium chlorideto the corresponding alcohol. The solution were well mixed and a sampleof cotton printcloth was impregnated with the solution which wasmaintained at 10 C. or below. The remainder of the operation was exactlyas described in Example 1. The washed and dried sample of treated fabriccontained 0.90% nitrogen.

EXAMPLE 12 A swatch of rayon fabric was treated using the technique ofExample 1 with the solution of Example 4. The nitrogen content of thereacted and washed sample was 0.73%.

EXAMPLE 13 Woodpulp from slash pine, 10 g., was impregnated with thesolution of Example 1 by soaking the pulp in the solution for about 30minutes. The pulp was separated by vacuum filtration and pressed untilthe wet pickup was about The pulp was then spread in a thin layer on acrystallizing dish and placed in an oven at 140 C. for minutes, thenwashed and air-dried at room temperature. The nitrogen content of thissample was 0.39%.

EXAMPLE 14 Chemically pure corn starch, 10 g., was soaked in thesolution of Example 6 for 30 minutes. The reacted starch was separatedfrom the solution by filtration and treated as described in Example 13.The nitrogen content of this sample was 0.83%.

EXAM'PLE 15 A quantity of 17.2 g. (0.10 mole) of2-chloroethyldiethylamine hydrochloride was added to 100 ml. of 2 normalaqueous sodium hydroxide, and the mixture was shaken 15 minutes. Aswatch of cotton fabric was treated with this solution by the process ofExample 1. The analysis of this cotton sample showed a nitrogen contentof 0.37%.

EXAMPLE 16 Using the technique of Example 4 but varying the solution sothat it would contain 1 mole of DAC and 1 mole of potassium hydroxide in1000 ml. of solution, a cotton printcloth was processed as before.Analysis of this sample indicated a nitrogen content of 0.42%.

We claim:

1. A process for the preparation of diethylaminoethyl derivatives ofpolysaccharides, comprising:

(a) mixing aqueous Z-chloroethyldiethylamine hydrochloride with aqueousalkali hydroxide to produce a water-insoluble liquid product,2-chlorodiethylamine,

(b) separating the water-insoluble product from the contaminants,

(c) mixing the water-insoluble product with about five times its weightin water and shaking thoroughly for about 15 minutes thereby forming anaqueous solution of diethylaziridinium chloride,

(d) impregnating at room temperature of a polysaccharide materialselected from the group consisting of cotton cellulose, wood cellulose,starch, and regenerated cellulose with the aqueous solution ofwatersoluble diethylaziridinium chloride from step (c) in the ratio ofapproximately 1 to 5, respectively, and

(e) dry curing the impregnated fabric.

rial.

2. The process of claim 1 wherein the polysaccharide is cottoncellulose.

3. The process of claim 1 wherein he polysaccharide is wood cellulose.

4. The process of claim 1 wherein the polysaccharide is regeneratedcellulose.

5. The process of claim 1 wherein the polysaccharide is starch.

6. A process for the preparation of diethylaminoethyl cotton fabrics,comprising:

(a) mixing aqueous 2-chloroethyldiethylamine hydrochloride with aqueousalkali hydroxide to produce a water-insoluble liquid product,2-chlorodiethylamine,

(b) separating the water-insoluble product from the contaminants,

(c) mixing the water-insoluble product with about five times its weightin water and shaking thoroughly for about 15 minutes thereby forming anaqueous solution of diethylaziridinium chloride,

(d) impregnating cotton fabric with the aqueous solution of step (c) and(e) dry curing the impregnated fabric.

OTHER REFERENCES Roberts et al., Textile Research Journal, vol. 40, No.3, March 1970, pp. 237-243.

GEORGE -F. LESMES, Primary Examiner J. CANNON, Assistant Examiner U.S.Cl. X.R.

8120; 260231 R, 231 A, Dig. 6, 2.1 R, 2.2 R, 2333 R

